醋酸丙酸纤维素的性质及应用

文章综述了醋酸丙酸纤维素的物理性能、化学性能、加工性能和溶解性能,以及醋酸丙酸纤维素在涂料、塑料和油墨等方面的应用。     

国内醋酸市场分析与预测

醋酸在化工、医药、纺织等行业有极其广泛的用途,可用于食品添加剂、杀真菌剂以及化纤生产等。其中最大用途是制造醋酸乙烯酯单体(简称VAM);其次是衍生成醋酸乙酯或醋酸丁酯等(作为涂料、油墨等的溶剂)、醋酸酐(往下生产醋酸纤维素等)及TPA/DMT等聚酯纤维原料的制成溶剂。目前,在我国生产VAH和醋酸酯是醋酸的主要用途。     

纤维素醋酸酯合成研究进展

纤维素醋酯有多种酯化值,泛指纤维素二醋酸酯和纤维素三醋酸酯。纤维素醋酸酯性能优良,用途广泛,产品附加值高,生产过程无污染,原料可以再生,适合可持续发展。文章综述了纤维素醋酸酯的合成研究进展。     

纤维素醋酸酯合成研究进展

纤维素醋酸酯有多种酯化值,泛指纤维素二醋酸酯和纤维素三醋酸酯。纤维素醋酸酯性能优良,用途广泛,产品附加值高,生产过程无污染,原料可以再生,适合可持续发展。文章综述了纤维素醋酸酯的合成研究进展。     

硝酸纤维素生产技术

1 基本原理及其性能 硝酸纤维素又称硝化纤维素或硝化棉,外观为白色絮状纤维,比重1.60左右,不溶于水,能溶于有机溶剂。用硝酸纤维素制得涂料的涂膜坚硬、耐久、光亮,并具有一定的抗潮及耐化学腐蚀性。它由脱脂棉或短绒纤维素经浓硝酸存在下发生酯化反应而制得。     

HPAM/Cr~(3+)弱凝胶调剖堵水剂的研究进展

介绍了部分水解聚丙烯酰胺和醋酸铬交联剂复合而成的一种弱凝胶调剖堵水剂,研究其成胶机理、调剖堵水机理及胶体性能。     

非离子型纤维素对泡沫稳定性的影响研究

泡沫复合驱以其优越的提高采收率性能受到现场的重视,但泡沫在高温油藏容易破裂,大大减弱其提高采收率能力.目前通常会添加一定的稳泡剂来增加泡沫的稳定性,本文研究了新型稳泡剂非离子型纤维素对泡沫稳定性的影响.常温下泡沫的稳定性随着纤维素浓度的增加而增强.高温条件下,起泡能力也较好,质量分数为0.2%的非离子型纤维素在高温下具有较好的提高泡沫稳定性的能力.酸性和碱性环境对非离子型纤维素的凝胶化温度几乎没有影响,其能够在PH变化时,随着温度的变化发生可逆的凝胶化反应,非离子型纤维素稳定泡沫的能力受PH的影响较小.     

交联聚丙烯酰胺蓄冷剂的研制

以自制的部分交联聚丙烯酰胺为主要原料,加入羧甲基纤维素、甘油等助剂配制成水凝胶,成型装袋成为蓄冷产品,对蓄冷产品进行性能测试,结果表明制得的产品具有良好的蓄冷性能。     

乳胶漆的配制方法

目前市场上的化工建材紧俏，如广泛用于室内外建筑的徐饰材料“乳胶漆”，十分畅销。今特介绍其配制法：（1）主爱原料及配比聚蜡酸乙烯乳液（含量50％）420份，钛白粉260份，滑石粉80份，淡甲基纤维素1份，聚甲基丙烯酸钠0，8份，亚硝酸钠3份，醋酸本汞1份，六们回酸钠1。5份，水232．7份。（2）制备方法特铁白粉、滑石粉及水投入高速搅拌机内，开动搅拌，使分散至一定细度，然后加人聚醋酸乙烯乳液，高速搅拌，然后加入校甲基纤维素、亚硝酸钠等其余均料，搅拌过滤，即可。门）适用范围与特点新型的乳胶漆，以水为稀释剂，代替有机溶剂。…     

丙醛丙酸市场缺口大

据 了解 ,我国目前尚未实现丙醛工业化生产 ,丙酸工业生产也几乎是空白 ,仅有少量来自木材干馏和轻质烃氧化制乙酸过程的副产物 ,供不应求。我国丙醛生产基本属空白。丙酸的研究和生产起步也较晚 ,仅有几家企业建有小规模轻油氧化生产丙酸装置。而近年来 ,我国丙酸需求量猛增。首先是由于我国的饲料工业取得了长足发展。 1 993年我国饲料产量已跃居世界第二位。 1 995年混配饲料产量为 42 0 0万 t,消耗丙酸 41 5 0 t。预计 2 0 0 0年我国混配饲料产量将达到 1亿 t,需丙酸 9880 t。其次 ,我国谷物和油料作物每年都有一部分发生霉变 ,解决办法…     

气相沉积涂层技术用于钻探机具的硬质润滑薄膜

钻探机具,要带有最优的耐磨特性,以及最优的耐蚀特性;在苛刻的态势下,也应妥善运转。钻探机具固有的表面性能,涵盖了配件的耐磨特性。载能粒子惯常的沉积状态,关涉着摩擦薄膜特有的构架问题。要提升配件原有的耐磨特性,就应提高机具表层硬度,用气相沉积技术,接纳复合架构下的、多层级高结合力的层积思路,制备出硬度较高的表层。这样制备好的润滑薄膜,带有独特构架及特有的性能,能提快原有的钻探速率,供应可用的新技术。     

商业物业与居住物业在我国的发展现状对比与对策分析

随着社会的发展,近年来,物业市场呈现出不同的态势。在激烈的市场竞争中居住物业与商业物业体现出不同状态,这一社会现象社会各界对此给予关注。从物业管理企业的发展现状进行对比、分析成因,从居住物业管理的现状出发,分析了居住物业弱势形成的原因,根据自身特点、借鉴商业物业强势发展现状提出解决该问题的几点建议。     

The foreclosure discount: Myth or reality?

Foreclosed properties sell at lower prices than do nearby non-distressed properties. Of particular concern, is whether there is a “stigma” foreclosure discount whereby REO properties sell at lower prices simply because they have been involved in foreclosure proceedings. To the extent that such a discount exists, arbitrage opportunities exist and the associated market failure has significant policy implications. We examine the foreclosure discount from a different perspective than prior researchers by comparing holding period returns earned by purchasers of REOs with those earned by purchasers of similar non-distressed properties. Our results show that the majority of REO purchasers do not earn economically significant excess returns. On average, the implied market discount is less than typical transaction costs. We also find evidence that REO properties and buyers vary systematically from their counterparts in the non-distressed market segment and that REO attribute prices differ from those of non-distressed properties. Overall, our evidence suggests that the market for REOs operates efficiently: lenders are not irrationally dumping REO properties and REO investors are not reaping extraordinary profits.     

基于多案例的中国民营企业控制权代理特征研究

本研究旨在探索中国民营企业控制权代理行为的特征,为中国民营企业突破成长困境、实现可持续发展提供理论启示。本研究采用扎根理论方法有效捕捉到了中国民营企业控制权代理特征的内涵,并通过问卷法进行了数据检验。结果显示:中国民营企业控制权代理特征包括授权、自我效能和适应三个维度,其中授权是代理行为的基础和动力,自我效能是代理人的行为特征,适应反映了民营企业控制权代理行为的持续机制;另外,这三个维度在不同行业类型、企业规模和战略类型的民营企业中存在显著差异。     

国家审计理论属性的探索

对国家审计理论属性进行探索可以发现,作为审计理论的一个基础命题,国家审计理论属性具有多重性.政治性是它的特有属性,实践性是它的基础属性,开放性是它的方法属性,创新性是它的动力属性.弄清国家审计理论属性有利于人们从不同方面、不同层次认识国家审计理论,提升国家审计理论研究水平,形成更高质量的国家审计理论研究成果,发挥理论指导实践的作用.     

钢桥面沥青混凝土铺装施工技术

由于钢材的弹性模量、导热系数及热膨胀系数均与沥青铺装层有较大差异,因此,钢桥面的铺装技术一直是个难点。环氧改性沥青混凝土具有比普通沥青混凝土优异得多的物理、力学性能,如高强度、优良的抗疲劳性能、良好的耐久性及抗老化性能,是受力特性异常复杂的正交异性钢桥面铺装、超重载交通道路、城市道路交叉口、公共汽车停靠站等特殊路段的理想材料,但由于环氧树脂和固化剂的不可逆反应,其施工要求非常严格。通过厦门市五石路钢箱梁桥面铺装环氧沥青混凝土的应用,从原材料质量、混合料性能、配合比设计、拌和生产、现场摊铺等施工技术作了研究和总结,对环氧沥青的施工温度、施工时间、碾压以及接缝的处理进行了研究,提出了关键工序中的控制指标和相关的控制方法。工程实体质量取得了较为理想的结果。     

An Examination of Mortgage Debt Characteristics and Financial Risk among Multifamily Properties

Using the 1996 Property Owners and Managers Survey (POMS), the authors (1) examine the mortgage debt characteristics of multifamily properties; (2) estimate the size and potential for growth of the multifamily mortgage debt market; and (3) examine the financial characteristics of multifamily properties, each with particular attention to differences by property size. While the authors find that the POMS suffers from severe missing value problems, their analysis indicates large differences in the likelihood that a property has a mortgage, the interest rate conditional on having a mortgage, and indicators of financial distress among properties of different size. They also find that smaller properties, with large potential for growth in multifamily mortgage lending, have much higher concentrations of low- to moderate-income tenants but that larger properties provide the bulk of units that serve these renters.     

Competitive equilibria in Shapley–Scarf markets with couples

We investigate the existence and properties of competitive equilibrium in Shapley–Scarf markets involving an exogenous partition of individuals into couples. The presence of couples generates preference interdependencies which cause existence problems. For both cases of transferable and non-transferable income among partners, we establish properties for preferences that are sufficient for the existence of an equilibrium. Moreover, we show that these properties define a maximal preference domain.     

铜粉、石墨改性UHMWPE复合材料摩擦学性能研究

通过制备铜粉、石墨粉改性的UHMWPE复合材料,考察了复合材料的力学性能及摩擦学性能,本文对此进行了详细的探讨。     

Topological properties of reconstructed credit networks and banking systemic risk

Financial bipartite networks provide channels for contagion risks and their topological properties determine financial stability. We enrich the bipartite network reconstruction methods proposed by Ramadiah et al. (2020) and extend them to the Chinese banking system. By comparing the reproducibility of the real credit market and the corresponding systemic risk, the impact of topological properties for different reconstructed bipartite networks on financial stability is analyzed. The empirical evidence shows that network reconstruction methods based on maximum entropy ensembles capture more properties in the real credit network. It also highlights that the different systemic risk level is mainly contributed by the topological properties based on common exposures. These analyses for topological properties provide regulatory insights for systemic risk prevention. It shows that reducing credit similarity across banks while increasing credit diversification in different sectors helps to control systemic risk. The results imply the possibility of increasing financial stability through the macro-regulation of the credit market structure.